*{
    margin: 0 0;
    padding: 0 0;
}
li{
list-style: none;
float: left;
}
.container{
    position: relative;
}
.banner{
    position: absolute;
}
.banner_img{
    width: 100vw;
    height: 100vh;
    display: block;
}
.button_container{
    position: absolute;
}
.on{
    background-color: rgb(57, 168, 172);
}
.button_container_circle{
    border-radius: 50%;
    width: 10px;
    height: 10px;
    cursor: pointer;
    background-color: #fff;
    margin-right: 5px;
    float: left;
}
.arrow{
    width: 40px;
    height: 40px;
    position: absolute;
    cursor: pointer;
    line-height: 40px;
    text-align: center;
    font-size: 36px;
    font-weight: bold;
    z-index: 200;
    background: RGBA(0,0,0,.3); 
    color: #fff;
    text-decoration: none; 
}
.prev{
    left:20px;
}
.next{
    right:20px;
}
